The Yellowstone Caldera
It should be no surprise that Yellowstone National Park sits on a large network of subterranean chambers of molten rock and gases. What is a surprise for many is that it is the biggest volcano in the world. It is so large that it is considered as a super volcano. The last major eruption occurred about 640,000 years ago, ejecting 8,000 times the volume of ash and lave from the Mount St. Helens explosion.
